Q. For a certain change, the value of ëU is -2.37 kJ. During the change, the system absorbs 650 joules. How much work did the system do?
Q. A steam power plant with a power output of 150 MW consumes coal at a rate of 60 tons/h. If the heating value of the coal is 30,000 kJ/kg, determine the overall efficiency of this plant?